"Imagine a phone that could run real Remote Desktop. Real PowerShell. Anything that can run on your desktop PC. Imagine 'phablet' form factors, similar to today's Samsung Galaxy Note 2, which could dock to a desktop setup and utilize an external display, keyboard, mouse, and other peripherals. Imagine a single set of APIs that work everywhere. Imagine that Phone isn't a whole separate platform, but an app. An app that runs on Windows. Real Windows. The Windows Phone team could never make that happen. But the Windows client team? You betcha. Make it happen, Microsoft. It's time to take the phone seriously." I have never agreed with Thurrot as much as I do right now.

Or, you can run the exact same OS on each device, with interfaces that are optimised for each screen. Afterall, that's exactly what Linux + KDE allows you to do via plasma (plasma-workspace, plasma-netbook, plasma-active).

Except that Linux is a kernel, not an OS. The Linux that runs on desktops is not the same Linux that runs on phones, even though they probably have most of the same internals. So that's more along the lines of what I was talking about

Except that they are the same. Not the same binaries, but built from the same sources.

I'm not a developer, but I would think that two things compiled from the same sources doesn't mean they're the same. Like, if you're compiling for phones, do you need code in there to access an x86 CPU? Would you need to include code to handle an LTE chipset or auto-rotation into the desktop version? Would the phone version need a driver to access a Sound Blaster card?

All I'm saying is you don't need to have an IDENTICAL feature set between phone/tablet/desktop versions. Seems that the OS's would be a lot more efficient if they were modularized for the platform they're going to be installed on, even if they still have most of the same internals where it really matters.